Ya Ed asked what bars I was running and what aero. Thx always appreciate some constructive input. It sounds like maybe the setups aren't too far off if I have the smaller front bar (honestly not sure why I didn't purchase the big bar up front, probably just an oversight on my part thinking I didn't need it) and larger rear bar. It sounds like it's definitely in the realm so I should be able to get things set nicely with the shock settings. There are definitely different opinions on how to setup the car. Some folks will say a bit of understeer (especially w/o real aero) will help you put down the power easier on corner exit, whereas more neutral/touch of oversteer obviously makes it more responsive to steering inputs. I like the car feeling pretty responsive steering wise but neutral and I find it fun changing the settings and getting the suspension dialed in. I got the car pretty dialed in neutral in a couple sessions w/ your starting settings you recommended on the BC coilovers. *hattip*

 

So I finally got the coilovers installed and everything back together. Getting the ride height set was a slow process of jacking up the car, raising/lowering a corner, lowering the car back down, rolling the car back and forth a couple times, measuring the height, and rinse repeat a bunch of times till I got the height set at each corner to the same as before. The covers that came with the Xidas are nice but a little bulky. Not sure if anyone had the same experience but I will probably go back and add zip ties around the axles as I don't want them to rub on the covers. Here's a picture of a coilover on the workbench before install.


One other small thing on the todo list was to tension the manifold brace w/ the engine hot. Fortunately it's pretty easy to access. After going for a drive I put just a little tension on the rod and locked the jam nuts in place. It was previously tensioned when cold. Will this make a difference? I don't know, but I figure it's probably better done hot.



I like the two BMM Kan gauges. The 2nd one that replaces the coolant gauge should be handy for keeping an eye on things. Hopefully I can catch any alternator issues ahead of time if they arise again. The gauges are very legible which is handy.



It's a nice day here so I took the car for a quick drive and wanted to see how the Xidas felt. The initial settings were 5 clicks from full soft for the front and 3 clicks for the rear. I figured it would be too soft and it was, but I was happy that ride quality is greatly improved. Quality shocks make a big difference. The high speed dampening is much better over things like bumps which helps ride quality. I will bump up the shocks another few clicks and see how it feels. On 5/3 no surprise it felt a little uncontrolled (floaty/bouncy) for the stiff springs, but for the street with rough roads softer is better than too stiff. Snapped a picture of the engine bay and car (it's filthy).


Happy to have the car back together, running, and warm weather on the way. It's almost like a big go kart.

 

Wait, just to clarify, you didn't make the same mistake I did with setting ride heights on these did you?

When I got my Xidas, I painstakingly went through the process you described, adjusting preload on each coilover individually until my ride heights were perfectly even left to right. I found out I was wrong quickly and was told to just set preload equally (down to the millimeter) left to right, and not worry about the resulting difference in left to right ride height. Then average out your L/R ride heights on each side of the car to determine your total rake. At that point, I was told to set rake by raising or lowering both left and right preload collars simultaneously on the front or rear.

I got my L/R ride heights perfectly even after installing my Xidas, but this resulted in a large disparity in preload adjustment between all four coilovers. After aligning my car, I took it for a spin to find that it wanted to pull right HARD haha. Apparently all it usually takes to corner balance a car with springs this stiff is one or two rotations of the preload collar. Anything more will really throw off your corner balancing.

Maybe I misinterpreted your post, but just wanted to throw that lesson I learned in there in case it could save some headache down the road haha. Car's looking good as are the dash gauges! Excited to hear your track impressions after everything you've done.

 

I'm not sure.. maybe? I didn't worry about L/R ride heights but I just set the height to the exact heights the car was at before, at each corner (left is slightly higher than right to make up for driver). I adjusted preload at each corner to set the ride height. According to the install instructions for the Xidas it says one full rotation of preload in the rear is equivalent to roughly a 2mm adjustment up/down. That's close to 1/16". I expect things to settle a bit after driving it so I might have to raise it up a touch but we'll see.

I corner balanced the car prior to installing the turbo so I'm sure that's all off now, but I should go back and see what the height at each corner was then. It should be very close to my current ride height.

 

I think what Zak is saying, is that unless you actually have scales to properly cross balance you should set the L/R 100% identical/even, and only adjust F/R balance for the rake you desire.

Back in the day I tried to make changes at each corner, with a ballast in the car to emulate my weight, and ended up with one wonky *** handling car. Not saying yours are bad, just something to think about.

 

Nate said it better than I did haha. Yeah, my interjection was basically recommending to even out the L/R preload collars until corner balancing the car. I did misinterpret your post a bit. Didn’t realize you were setting ride heights to mirror what they were before.

 

Congratulations on the Xidas, Slow. Looking forward to seeing how you like them after they're adjusted. Those KaN gauges look great.

This is helpful info Z, thank you.

 

How do you like the turbosmart blow off valve? I ended up ordering one since I tried a few I had lying around and wasn't happy with any of them. Do you get fluttering at low boost and/or just putting around town?

 

No complaints. Seems to work fine and no issues so far. I haven't noticed any fluttering when it opens.

 

One thing I've known for a bit is the BMM ECU has boost control. I mentioned in some previous post (I think) that I wired up the mac solenoid for boost control. What I didn't realize is that the BMM ECU can alter the open loop boost control table with other blend tables based on other inputs! What that means is you can wire up a pot switch to have a more variable boost control, or for the simpletons like me, a simple high/low boost switch!

The switch will feed in 5V or 12v to the ecu on a mapable analog input. This input can then be used to add the blend table to the regular open loop table. Exciting and fun stuff. I still need to go back and program the fuel pressure safety and some other things the ECU has but this was a pleasant surprise and should be simple to wire up! I'm not going to go crazy, as the rods seem to bend like toothpicks but it'll be nice to be able to add a few psi if I want to for a couple laps or farting around on the street.

 

Nice, not a bad find there! Maybe I missed it but you haven't set up boost control yet in any regard, correct?

Damn, I miss messing around with boost control tables in TS haha.

 

I setup a couple aux switches recently for this exact purpose. The link can switch between boost and ignition tables, so I figured I could have a party switch that would increase boost, retard timing on decel and disable overrun fuel cut for some noise. Childish and ricer for sure, but I haven't committed to growing up yet.

I was thinking about what to use the second aux switch for and I'm thinking I'll use it as an AC fan override so I can force both fan's to be on regardless of temperature. That's pretty useful when sitting in grid between runs.

A rotary switch would be way cooler though. I've got a couple on my sim wheel and it's pretty fun to adjust brake bias or traction control with them. I had considered adding one and trying to use it to adjust launch control RPM on the fly, but I'm not sure if it's possible.

 

Nope haven't set up boost control at all. Honestly spool is pretty quick with the small 2560R so I'm not sure if I care too much about gaining spool time by switching to the boost solenoid vs just running off of wastegate. It'll be nice to be able to run a few more lbs of boost on the street and leave it on lower boost for the track. Not expecting to win any drag races with this thing but who doesn't like more powa.

So far so good with the Xidas. Did a little putzing around on the street on Sunday with 7 clicks front, 5 clicks rear and it's feeling pretty good. Noticeable change in 2 clicks.

 

You can use the 3D Launch RPM Table mode and setup the table to rotary switch inputs. Depending on the rotary switch you use, it would go through a Volt input or CAN Analog. There is a specific GP Rotary Switch function to setup the integer values for each voltage step. The configuration is also documented in the Help page.

I setup my launch control similar to Hondata using a Latched Launch Control. While under 15KPH and holding the clutch, it holds the RPM at the point where I pass 35% TPS. That way I can select a Launch RPM on the fly. I haven't tried it in the heat of the moment at autocross yet, so don't know how well it will turn out.

 

It's always good to have a rotary switch, you can use it to adjust multiple things on the fly, when they're difficult to feel out on the dyno. Launch RPM, boost, TC slip, etc. just spend some time to setup the table on the laptop, then change the parameter that uses it when you want.

Link doesn't actually have one, but the Haltech one is great:

https://www.haltech.com/product/ht-0...rxA9AqYH5RfuWv

 

So I got boost control "working" roughly (it's not working well just yet), but I was starting to think/wonder if even playing with it is smart. What is the "bend rods" torque territory on the 1.8l? Is 220-240 torque the limit? I did some poking around and it looks like some folks make ~250whp and around 200-210tq at 12psi, but is that "safe?" I have no clue what kind of power this motor is making. Assuming it's healthy and a good tune people seem to make ~200whp at ~7psi with a kraken top mount and 2560R. It looks like power is ~250whp and 210wtq with ~12psi? That seems like about the safe limit. It looks like some folks have boost at ~9psi peak torque and increase the boost level after say 5500 rpm to get more hp while maintaining peak torque. I figured I'd ask you guys what you thought was "safe?"

I'm probably dumb playing with boost control at all but what the hell..

This was one good link I found: https://bofiracing.co.uk/blog/how-to...5-miata-alive/

 

210-250ft/lbs seems to be the limit, it depends on how closely to 5250rpm you make that torque. The earlier the worse for rods. Get it dyno'd to check the power curve of your particular setup, then you'll know how much room you have to play with EBC.

 

What curly said, of course.

But FWIW, my car was making about 200 peak wtq at 12psi with the same setup, aside from the ‘95 engine. I think the chances of bending a rod at 12ish psi across the whole rev range is slim.

But yeah, definitely get that thang dyno’d lol.

 

Appreciate your guys' advice. I think the saga of playing with boost control for the time being is over. I thought it'd be a little easier but I probably need to clean up my tune a little more before messing with it. These little turbos spool so quickly so anything that is off gets magnified.

So just as a reminder I'm using the BMM ECU which controls a 3 port MAC solenoid. The issue I was experiencing is that I set boost cut to 86kpa (~12.8psi), and on fast shifts to the next gear higher in the rev range, I'd have boost spike a bit and hit boost cut. It doesn't do it all the time, but looking at the logs, I think the main issue is that my throttle tip in/AE is a little too high, which causes the car to run extra rich for a second (.75 lambda), which causes the turbo to spool more than steady state throttle. Maybe there's also some inertia at play w/ the turbo shaft accelerating hard after decelerating between shifts that causes some overshoot? I'm sure it's a few things. If I shift from 3-4, and ease onto the throttle it doesn't do it. So long story short, I'm gonna stop screwing around, as I don't have much leeway with the stock motor, and I'm honestly only talking about an increase of ~3-4psi. The more horsepowers felt good, but it always feels awesome right before it blows! The BMM ECU has closed loop boost control which will be fun to play with (I only used open loop), but it's time I don't have and I ought to be focused on other stuff.

I need to dedicate a bit more time to getting the tune really solid (mainly throttle tip in/ae set correctly, enable the fuel pressure compensation, and get the VE table nailed down). I also have idle droop intermittently it seems like when the car's hot where it overshoots the idle target to the downside and recovers. If anyone else with the BMM ECU has some opinions/advice/wants to compare notes, just let me know I'd be happy to. I guess the BMM discord is probably more suited to this discussion.

 

My setup did the same thing with overshoot. Full throttle pulls would result in a 2-3psi overshoot between gear shifts. Never thought about it until now, but that’s probably exactly where you don’t want boost overshoot. Right when you’re lower in the rev range and switching from no load to full load lol.